Method of producing pressed sheet glass



- 6 i927., Sept E. T. FERNGREN METHOD OF PRODUCING PRESSED SHEET GLASS Filed Nov.

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INVE N T En-' f l, l

. 40 L uniform hidmoss and then )lncguo the pirotallv rarrieil n )on a Carriage i3 movable Patented. Sept.. @i

ENOCH' T. FERNGBEN, OF TOLTDO, OHM), ,ASSIGNOR TG THE LIBBEY-OVVENS SHEET GLASS COJHFNY, OF TOLEDO, OHM), 3. CRFORATT OF GHI@ METHCD OF PRODUCNG PRESSED SHEET GLASS.

Application filed November 24:, 1924. Serial No. 751,82G.

rhe present invention relate@ to a nietliod liigij. is e transverse vertical section K of producingr pressed sheet gf'las. and han through the ire-i'iolishing chamber. 55 particular' reerenee to the manufacture of E'leretofore plate glass has been formed pressed glasssnitahle for plate glass nee. 'by rolling a lease ot" molten glass upon a.

An in'iportant olijeet ot' the .invention is tahle, after 1which the blank thus formed to provide means 'for Continuously 'iowing hasl heen ground and polished to give a sheet a ribbon. ot plastie glass upon one loi av ot.' ,irlaes suitable .for piate glass use. Due @0 plu ralit).Y of n'ioldsl in a nianner wherein the to the irregularities and other surface derihbon een be separated into individual teu'mities 'toi-ined by the rollingy pr cess, it sheets which are Capable ot heine" liiesseil has, heretofore been necessary lo produce a to a uniform thickness, after which the blank suliatantialljtT thicker than thethictsheets can be suitahlj,P polished it'or plate ness of the sheet le.-ired, which hes neeessi- @5 glass use. tated an expensiije and tedious surfacing Another object is to keep the ribbon et opeizfition to gire a 'sheet of the necessary '15 glass in such inent condition at points where dimensions.

it is separated .into individual sheets that, in aeeordanee with the present invention shears or Cutters may he eniplm'ed inthe it is the aiin 'to produce e Sheet of plate w por'lornnniee of the rletaelnnent oi' earh infli- ,filas-,s much more quickly and cheaply than vii'lnal Sheet from the deprisitingg; rihhon. has heretot'ore heen possihie by substituting 2G '.tt lis also an object of this invention to the grirn'linrir and polishing operations hereimmediateyiehill the upper surface of each totoi'e resorted to `with a tiiwpoliahing arsheet which is detached troni the ribbon of rangement. This substitution is made pos- 75 glass t0 the end that this snrlaee layer sible by employingv an apparatus such asis thereon will possess about the saine degree shown in the drawings. f 25 of rigidit' at the lower surface ofthe sheet, In the drawings the numeral t3 designates While the Lniierior portion oli' the sheet is as the discharge end of a tank' furnace.. and yet m plastic gta-te, hasl arranged at the hottoin thereof a suie 83 A further Qbjggt of the invention ig to ahie refractory tile G having the Curved end provide means of this nature vy'herein a 7. The opening 8 of the discharge end is quantity of glass is Continuously overlio'wed Cent-rolled hy a shear ealte if). r'he molten in rihhon-like formation upon a movable f "lass i() therein eontinnaily overfiowed mold and kept in atiuent state thereon. after to produro a rihhon 11 which is deposited 85 Vphch the pyQgS/Qd t() a Unifoi'ln U'WH (i110 OiE it Plllllity Of lIlOld SGC'tlODS thiQkn/yg and then fr@-p0jghed t0 gir@ a 'The mold i2 may he composed oi nickel sheet of glass suitable vior plate, glase uses. '11i its Upper portion. or may be lined with Still another object' ot' the invention is to :i 1ioi-eo1'i^ isi\'e alloy to present a surface form a sheet of glass by iirst iiowingr plastic Whivh may eontaet -with the rihl'ion l1 with- 99 glas-g in Sheet 'formation upon a nlolrlj prgjusmit iii :my XYHY 'm'lllllitlltly SpOillIizQ 01' illin;r the glass thus deposited on 'the mold to 'Uiirse' the ola.; surf-aro. The mold 12 ig sheet in a. vertical position and iire-polishupon the, rails4 15. The nioids l2 and caring the Same by preferably radiating heut, ringe lli are' 'formed at, their entli in n mmh 95 Other olijeets 'and advai'itatfeg of the inner to permit a drivin;r member 16 to be ar- 4D COUPS@ of the following'description. ille. eai'ne.

In the drawings wherein like numerals The speed of movementA to be given to are employed to designate like parte the series oi' molds and carrie by the driif'- '1w throngjhont'tlie sanie-- inonieniiwrs 1G depende on the nature oi Fig. lis a fragmentary iongitndinal View., 'the glass. its teinpin'aiaie intl iuerlfcy., and. partly in section, through a portion. ot the itsl quantity movement ond speed or fall of apparatus, tiow over the carre 7, which rehition- Fig, 2 Vis a' fragmentary top plan of e ship when properly :Mij: ted tletrmtlet "the m5 portion of the apparatus7 andv subsequent thickness et me sheet.

2 meines .As the sheet flow 11 contacts with the upper surface of each mold 12, which mold surface in normal practice should be preheated to a slightly noticeable tinge of red towards its edge portion, the contacting surface portion of the ribbon l1 receives more coooling along its medianl section, lont-in:

. is most easily or readily dissipated.

In order to prevent loss ci' heat 'from the yglass at the point where it' is to be severed, each driving member 16 is adapted. to canse a spacing between the edges ot the mold tables 12, by which arrangement the Lglass stream flowing from slab G is caused to bridge over the between the molds and thus preventJ it vtrom comingY in contact with. an heat-absorbinfr media.

lilach mold tablge l2 is provided with a rknife or cnt-oil im; lement lei which may be secured to the rear end thereof, and as.

the ribbon 1l is strung over 'the space between the molds 12 this implement la forms the extreme rear edge of table 12.

The driviiny members 16 are carried by a link chain l?? operable over s itable drums 18. The chain 17 rides in its upper draw upon the table 19. After the mold 12 has passed under the slab 6 and has a quantity of glass in sheet lform deposited therein, 1t .is advanced to and stopped at plunger member 20. Arranged directly bel'owthe plunger member 20 is a stationary support 21 to hold the mold l2 iirmly during the press ing: operation. f

During movement of, the glass ribbon 1l to the. pressing station7 heat should be applied thereover, and particularly along the edge section of the glass in order that a slightly higher degree ot fluency sustaining' temperature be maintained within the mar ginal body ortions et the glass sheet or ribbon 1l, -or which purpose the heating; enclosure 35 is located above tbe mold tables 12 andthe burners 3S provided for the local heating of the edge portions of tbe/ glass sheet. f

The plunger 20 is provided with a knife edge or cutter 22 which is mounted in'posb tion at the rear end thereof, and is adapted to ,cooperate with a knife. edge la at the rear end of each mold 12 and to sever the ribbon 11 between adjacent molds prior to the pressing operation.

The actual operation to advance each mold l2 into position for the cutting and pressingy 0f the glass ribbon may readily be performed automatically by the employment of suitable coordinated and synchronized mechanisms of well-known type, but as here shown these steps are performed and controlled partly manually.

As tbe gear rack 27 beneath each mold carrier 13 rides over the gear 25 during the forward movement of the carrier 13, the operator, by turning the hand-wheel 26, rotetes the pinion 2A- and gear 25 toadrive the rack 27 and thus give additional forwarding impluse to each 'advancing carrier 13, by which the operator is enabled to pull each mold l2 forward into cutting and pressing position with just enough gradual acceleration in speed to slightly tension the glass ribbon 11 at the point where it is spanning' the space between the molds, so that as the mold 12 is within aV fraction of an inch from the pressing position and needs to be moved but slightly before being' stopped, the maXi mum of stressing tension had in the stretched portion of ribbonv l1, at which instant the knife 22 of the descendingr plunger 20 severs the glass sheet or ribbon 11 by a scissor-like cooperative movement with knife edge 14.

rl'he actual pressing or stamping operation on each severed glass sheet must be unusually speedy7 and of a fleeting duration unless the plunger 2O is highly heated when slightly more of pressure dwell may be allowed.

The reason for this is that the ribbon 11 as flowed, deposited and heat-treated, will be o'i nearly uniform thickness so that `very little of glass displacement is required to get equal thickness, and that a quickly pern formed pressing or flat stamping action lessens the stresses in the ycontacted glass surface and in the as yet `Huent glass body ot sheet, thereby somewhat permitting a slight readjusting movement of the glass after the flattening impact.

At the time the pressing actionis per fonmed the sheet body on mold 12 is less hot', but isstill fluent so that much less of heat absorbing Contact is required to give the required toughness and thickness of skin to the upper surface layer thereon.

vWhen the mold is in position as indicated in dotted lines in 1. the plunger is shown at the instant of Contact as'the cutter member 22 severs the ribbon 1L` while at the same time a glass flange 23 will be formed on the succeeding sheet section. The plunger 2O is pressed against the glass to ive a sheet of uniform thickness, after which the mold and carriage are moved to a fire-polishing chamber 24. This is accomplished by means of the pinion and gear drive 25 operable by hand-wheel 26 which engages the rack-bar 27 carried by the carriage 14.t on its lower surface. When the mold is in position in 'front of the re polishing chamber 2li, it is tilted upon its carriage in a mann ner that the extension or daags 23 engages louv :ie/insee a hook 27 which is supported by means ot a roller or rollers 28 on a track 29.

The sheet 30 is then conveyed through the fire-polishing chamber 24., Which is preferably constructed to act upon the sheet by means of radiated heat. To'aecomplish this,

- ar 'anged in the fire-polishing chamber 24 are two spaced preferably carborundum plates 31, against which play flames 32 from burners The speed of the sheet through the tire-polishing,- chamber is controlled according to the amount ot heat radiated through the ca-rborunduin plates 3l. Due

' to the fact that theshelet is hung in a vertical position and that the flame does not actually come in Contact with the sheet a perfectly flat, smooth and uniform sheet can be produced. lf it is desired, the tire-polishine` can be accomplished by a direct thune,

but radiant heat will in most eases prove more satisfactory when making plate glass. After the sheet 30 has been brie-polished,

it is then passed through an annealingleer to gradually cool the same.

From the foregoingit will be scenthat the ribbon '1l is formed by an overliov,Y of

,glass from a. suitable source, which ribbon' isl of the approximate thickness of the desired size of sheet. After 'the ribbon has been placed upon the mold. it severed and then pressed to an absolute uniform thickness, after Which it is tire-polished to give the desired finish. By means Qt the molds and track Aarrangement shown, it is possible to have a continuous method of producing plate glass blanks of uniform thickness. it is also desiredy that the lower face of the plunger Q0, which, as shown, is purely dia- `Qrammatir, be lined or covered with a non-corrosive alloy.

lt is also to be understood that the form ot the invention herewith shown ano described is to be taken as the preferred embodiment of the samegmd that various changes in the shape, size andl arrangement of parts may be resorted to Without departing from the spirit of the invention or the scope oit the subjoined claims.

Claims:

l. The process of producingr sheet glass, consisting in flowing a quantity of glass into a mold, pressingV the quantity of'glass into sheet form, and then tire-polishing the same.

2. The process of producing sheet Iglass, consisting in flowing a. quantit'7 of. plast-ic ,glass into a mold in sheet form, pressing the sheet to uniform thickness, and then tirepolishing the same.

3. The process of producing sheet glass, consisting` in flowing a quantity et' plastic glass into a mold in sheet form, pressing; the sheet to uniform thickness, suspending the same in a vertical position, then firepolishingr said sheet.

4. The process of producing sheet glass,

consistingI in continuously flowing a ribbon of plastic glass into a plurality ot' molds, severing the ribbon between adjaeei'it molds, pressing each piece thereof into a sheet of uniform thickness, and then lire-polishing the same.

rllhc process of producing sheet glass, consisting in continuously flowinga` ribbon of plastic glass into a ph'irality ol" molds, separating; the ribbon with individual sheets. pressing each sheet to uniform thickness, tire-polishing,` the said sheet, and then annealing the sameL t3. The process of producing sheet glass, consisting in continuously flowingT a ribbon of plastic glass into one of a plurality of moving molds, severing the ribbon between adjacentmolds, pressing each piece thereof into a. sheet of uniform thickness, tire-polishing each sheet, and then annealing the. same.

T. The process of producing sheet glass, consisting in flowing' a quantity ot ,f rlass into a. mold in sheet form, press-incr the sheet to a uniform thickness, andlthentire-polishing the same by radiated heat.

8. The process of producingsheet glass, consisting in.overflowingT a source ot'- glass in ribbon form upon a mold, pressing the same to a uniform thickness, and then fire-polishing the same. 95

59. The process of producing sheet glass, consisting in overflowing' asouree of glass .in ribbon 'form upon a. mold, pressing,r the same to a uniform thickness, and then fire-polishing the saine with radiated heat.

l0. lThe process oi producing sheet glass, consisting` in overllowing a source of glass in ribbon form upon a plurality of moving molds, severing the ribbon between adjacent molds, pressing each section to a nm'- forin thickness, fire-polishing each piece, and then annealing the same.

il. The method iioi'niing plate glass, consisting in flowing molten glass in ribbon formation upon a series of molds which are spaced from one another, in maintainingY the fluency of the glass While it is received by each mold` in cutting the ribbon between the molds to torni detached sections, in flattoning each section as it is detached, and in applying heat to its surfaces to `rive polish thereto. V

12. rEhe method of forming sheet glass, which. consists in flovving molten glass in ribbon formation upon a series of moving molds, in heatinpr the edge portionsv of the molds and the edge sections of the ribbon, in heating the upper surface of the ribbon While it is received by each mold` 13. The method of forming; sheetglass, Which consists in flowing. molten glass in ribbon formation upon a series of moving molds, in heating the edge portions of: the molds and the edgre sections of the ribbon, in heating the upper surface of the ribbon,

while it is received by each niold, in succes sirely separating The rihhon into individual Isheets while immediately pressing each sheet to uniform thielinees.

lll. rlhe process ot producing sheet glass.y eonsirting: in ilowing a quantity of glass; onto one. of a plurality of molds. pressing the quantity ot glass to sheet forni with iiat means and-then polishing;- the saine by radiated heat.

15. The process of producing;` sheet glass, consisting in fiowing a quantity of glass onto one oi a plurality of niolds, pressing the edge portions oi, Ythe glass, pressing the quantity ot glass into sheet torni, and then tire-polishing the saine.

i8. The. process ot producing sheet glass, consisting in flowing a quantity of glass into a mold, heating; the upper surface of the glass and causing a localized heating of the edge portions thereof, pressing the quantity of glass into sheet forni, and then tire-polishing the same'.

19. The method of producing plate glass, consisting in flowing molten glass in ribbon formation upon a series of heated molds while subjecting the edge portions of the, ribbon to a-localized heat treatment.

20. The method of producing plate glass7 consisting in flowing molten glass in ribbon formation upon a series of heated molds while subjecting vthe edge portions 'of the ribbon to alocalized heat treatment, pressing the ribbon to a uniform thickness and then ire-poishing the saine by radiated heat.

Signed atv Toledo, inthe county of Lucas, and State of hio, this th day of *Novem-l ber` 192%.

Enoon fr. rnaneiann. 

